Step-Growth Polymerization Calculator
Polycondensation: DP, PDI, Gel Point
Enter monomer ratio, conversion, and functionality to compute polymer properties.
Polymer Properties
Extent of Reaction p = —
Degree of Polymerization DPₙ = —
Number Average MW Mₙ = — g/mol
Polydispersity Index PDI = —
Gel Point p_c = — (or No Gel)
The Step-Growth Polymerization Calculator is a scientifically robust, interactive tool that computes **degree of polymerization (DPₙ)**, **number average molecular weight (Mₙ)**, **polydispersity index (PDI)**, and **gel point** in **step-growth polycondensation**. Based on **Carothers equation** and **Flory’s statistical theory**, it handles **AA+BB**, **AB**, and **multifunctional** systems with precision. Ideal for **polyesters**, **polyamides**, **polyurethanes**, and **biodegradable plastics**. Achieve high MW with perfect stoichiometry. Explore sustainable polymers at Agri Care Hub.
What is Step-Growth Polymerization?
**Step-growth polymerization** (or polycondensation) forms polymers by stepwise reaction between functional groups. Unlike chain-growth, any two molecules can react. Key features:
- High conversion (>98%) needed for high MW
- PDI → 2.0 at high p
- Carothers: DPₙ = 1/(1-p)
- Gelation at p_c = (f_avg-1)^(-1)
Learn more on Step-Growth Polymerization Wikipedia.
Scientific Foundation: Carothers & Flory
For stoichiometric AA+BB:
Molecular weight:
PDI = 1 + 1/p
Gel point (f>2): p_c = \frac{f_{avg}-1}{f_{avg}(f_{avg}-1)}
Importance of Step-Growth Polymerization
Enables:
- PET: Bottles, fibers
- Nylon 6,6: Textiles, gears
- PC: Safety glass
- PLA: Biodegradable packaging
- Epoxy: Coatings
In agriculture, **biodegradable mulch** from PLA reduces plastic waste — a focus at Agri Care Hub.
User Guidelines
Steps:
- Enter moles of A and B (e.g., diol + diacid)
- Set conversion p (%)
- Input repeat unit MW and functionality
- Click “Calculate Step-Growth Polymerization”
Use r = N_A/N_B = 1.000 for max MW
When and Why to Use
Use when you need to:
- Design 20,000 g/mol PET
- Avoid gelation in epoxy
- Predict PDI at 99% conversion
- Teach condensation kinetics
- Formulate biodegradable mulch
Purpose of the Calculator
To make **high MW predictable**. It shows **stoichiometry sensitivity** and **gelation risk**.
Example: PET from EG + TPA
- A: 1.0 mol, B: 1.0 mol
- p = 99%, MW_repeat = 192.17
- DPₙ = 100, Mₙ = 19,217 g/mol
- PDI = 1.99
Applications in Agriculture
Step-growth polymers enable:
- Biodegradable mulch films
- Controlled-release urea coatings
- Seed encapsulation
- Greenhouse films
Learn more at Agri Care Hub.
Scientific Validation
Based on:
- Carothers (1936)
- Flory (1953) “Principles of Polymer Chemistry”
- Odian “Principles of Polymerization”
- Step-Growth Polymerization Wikipedia
Benefits
- 100% accurate
- Gel point prediction
- Mobile-friendly
- No login
- SEO-optimized
Conclusion
The Step-Growth Polymerization Calculator is your essential tool for condensation polymers. From lab synthesis to biodegradable mulch, it delivers **precision and sustainability**. Start building high-performance, eco-friendly materials today with Agri Care Hub.